In an information device such as an entertainment system as exemplified by a TV game machine, game data can be stored (saved) to or read (loaded) from a memory card that is provided. In using such a memory card, the card is inserted into the main unit (parent machine) of the information device. For this purpose, the memory card has an interface for connecting it with the main unit (parent machine) of the information device and a nonvolatile memory element for storing data.
FIG. 1A is a block diagram of the key parts of such a memory card. This memory card 10 has a control unit 11 for controlling its operation, a connector 12 for connecting it to a mounting terminal provided in a slot of the information device, etc. that is the main unit, and a nonvolatile memory 16 for storing data. Connector 12 and nonvolatile memory 16 are connected by control unit 11.
Control unit 11 is, for example, a microprocessor (so labeled in the diagrams). Used as nonvolatile memory 16 is, for example, a flash memory such as an EEPROM (electrically erasable and programmable ROM). A microprocessor is sometimes also used in the connection interface with the information-device parent machine as a control unit for interpreting the protocol.
FIG. 1B shows the control elements in control unit 11 of memory card 10. The memory card has a main unit connection interface 11a for connecting with the main unit (parent machine) of the information device, etc., and a memory interface 11b for inputting and outputting data to and from the nonvolatile memory.
A video game device stores game data, etc. in an auxiliary memory and has the function of reading it out again, and the memory card 10 is used as such a video game device auxiliary memory.
FIG. 2 shows an example of a video game device that uses a memory card as an auxiliary memory. Main unit 2 of this conventional video game device 1 has a disk mounting unit 3, which is accumulated in a roughly rectangular housing and in the center of which is mounted an optical disk, which is a recording medium on which video game application programs are stored, reset switch 4 for resetting the game at will, a power switch 5, an open button 6, which opens the cover of the disk mounting unit, and, for example, two slots 7A and 7B.
Memory card 10, which is used as an auxiliary memory, is mounted in slots 7A and 7B, and data such as the results of a game played on video game device 1 is sent from a control unit (CPU) 19, which is built into main unit 2, and is written into nonvolatile memory 16.
Multiple operation devices (controllers) not pictured can also be connected to said slots 7A and 7B, allowing multiple game players to play competitive games, etc. Simultaneously.
Instead of memory card 10 connected to memory card slots 7A and 7B of the present machine of the entertainment system, it has been proposed that a portable electronic device having the function of executing a TV game or other program be connected detachably. That is, it has been proposed that at least part or all of a program such as a TV game be downloaded, the program itself be executed, and if the program is a game in which characters appear, it be given the function of being able to allow the growth, etc. of the characters in the game.
Such a portable electronic device (child machine) can be used without modification as a portable information terminal, and by having a communication unit with other devices (parent machine or child machines), its range of application as an information terminal can be expanded, thereby leading to the stimulation of new demand for the entertainment system.
Such a portable electronic device must have the sound functions of producing music and sound effects in the portable electronic device itself in order to execute, separately and independently from the parent machine, TV games, etc. downloaded from the parent machine when it has been removed from the parent machine.
On the other hand, the functions, size, and price of a portable electronic device impose certain restrictions on the CPU and sound-system devices that it can have inside it.
Under these circumstances, it is desirable to obtain sound that is a clear, faithful reproduction of the original sound built into the game software.
Therefore an object of this invention is to provide a method for obtaining, in an electronic device, clear playback sound that is faithful to the original sound.
Another object of this invention is to provide, in an electronic device, sound functions by which playback sound can be obtained that is faithful to the original sound.
Yet another object of this invention is to provide an electronic device that has sound functions by which playback sound can be obtained that is faithful to the original sound.
Still another object of this invention is to provide an entertainment system that has a portable electronic device that has sound functions by which playback sound can be obtained that is faithful to the original sound.